1. Field of the Invention
The present invention relates to a DC/DC converter for driving a light emitting device and a driving apparatus having the same.
2. Description of the Related Art
In recent years, with developments in flat panel display technologies, flat panel displays have even been used in automobile instrument panels, as well as smart phones, game machines, and digital cameras, and are expected to be widely used in daily life in the form of various devices such as ultra-thin televisions (TV), transparent navigation devices, and the like.
As a flat panel display, a thin film transistor liquid crystal display (TFT-LCD) may mainly be used.
However, since the TFT-LCD requires a separate light source, the TFT-LCD has limitations in aspects thereof, such as accompanying ultra-thinness, ensuring viewing angle, and the like.
Accordingly, as a flat panel display that will be placed on the market in the future, an active-matrix organic light emitting diode (OLED) display may be widely used instead of the TFT-LCD as it has a wider viewing angle, a higher chroma value, and a faster response time, as well as not requiring a separate light source.
That is, among OLEDs, in the case of the active-matrix OLED, a response speed to moving images is measured using a microsecond (us) unit equal to 1/1,000,000 of a second. This is 1,000 times faster than the TFT-LCD having a response speed measured by a millisecond unit (ms), equal to 1/1,000 of a second, such that afterimage, problematic in the TFT-LCD, may be overcome.
In addition, since the active-matrix OLED is a self-illuminating type flat panel display, it does not require a backlight unit emitting light from a rear surface thereof unlike the TFT-LCD, such that the thickness and weight thereof may be reduced by ⅓, as compared to the TFT-LCD. Also, in contrast to the TFT-LCD, the active-matrix OLED has constant color reproducibility at high and low temperatures, and is a self-illuminating type flat panel display, so that a contrast ratio thereof is not changed through brightness or viewing angle.
In recent years, OLEDs have increasingly been used due to various advantages such as relatively low power consumption, relatively long life spans, environmental friendliness, and the like.
A driving apparatus for driving the OLED generally uses an AC/DC conversion circuit and a multi-stage DC/DC conversion circuit, and the multi-stage DC/DC conversion circuit may lead to problems such as a power conversion loss, an increase in manufacturing costs and the volume of the circuit due to the added converter, and the like, in a process of converting a voltage required for driving the OLED.
Also, the reliability of products, such as an active/passive device, an integrated circuit (IC), and the like, adopted in the DC/DC conversion circuit may be reduced.